[tip: perf/core] perf trace: Hook the 'vec' tracepoint argument with the x86 IRQ vectors scnprintf/strtoul

[tip-bot2 for Arnaldo Carvalho de Melo]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     df604bfda6f550f088e1cffcd098bfec0eee9cdf
Gitweb:        https://git.kernel.org/tip/df604bfda6f550f088e1cffcd098bfec0eee9cdf
Author:        Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate:    Tue, 15 Oct 2019 16:50:13 -03:00
Committer:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Tue, 15 Oct 2019 16:50:13 -03:00

perf trace: Hook the 'vec' tracepoint argument with the x86 IRQ vectors scnprintf/strtoul

Ended up only being useful when filtering multiple irq_vectors
tracepoints, as we end up having a tracepoint for each of the entries,
i.e.:

This will always come with the "RESCHEDULE_VECTOR" in the 'vector' arg:

  # perf trace --max-events 8 -e irq_vectors:reschedule*
     0.000 cc1/29067 irq_vectors:reschedule_entry(vector: RESCHEDULE)
     0.004 cc1/29067 irq_vectors:reschedule_exit(vector: RESCHEDULE)
     0.553 cc1/29067 irq_vectors:reschedule_entry(vector: RESCHEDULE)
     0.556 cc1/29067 irq_vectors:reschedule_exit(vector: RESCHEDULE)
     1.182 cc1/29067 irq_vectors:reschedule_entry(vector: RESCHEDULE)
     1.185 cc1/29067 irq_vectors:reschedule_exit(vector: RESCHEDULE)
     1.203 :29052/29052 irq_vectors:reschedule_entry(vector: RESCHEDULE)
     1.206 :29052/29052 irq_vectors:reschedule_exit(vector: RESCHEDULE)
  #

While filtering that value will produce nothing:

  # perf trace --max-events 8 -e irq_vectors:reschedule* --filter="vector != RESCHEDULE"
  ^C#

Maybe it'll be useful for those other tracepoints:

  # perf list irq_vectors:vector_*

  List of pre-defined events (to be used in -e):

    irq_vectors:vector_activate                        [Tracepoint event]
    irq_vectors:vector_alloc                           [Tracepoint event]
    irq_vectors:vector_alloc_managed                   [Tracepoint event]
    irq_vectors:vector_clear                           [Tracepoint event]
    irq_vectors:vector_config                          [Tracepoint event]
    irq_vectors:vector_deactivate                      [Tracepoint event]
    irq_vectors:vector_free_moved                      [Tracepoint event]
    irq_vectors:vector_reserve                         [Tracepoint event]
    irq_vectors:vector_reserve_managed                 [Tracepoint event]
    irq_vectors:vector_setup                           [Tracepoint event]
    irq_vectors:vector_teardown                        [Tracepoint event]
    irq_vectors:vector_update                          [Tracepoint event]
  #

But since we have it done, keep it.

This at least served to teach me that all those irq vectors have a entry
and an exit tracepoint that I can then use just like with
raw_syscalls:sys_{enter,exit}, i.e. pair them, use just a
trace__irq_vectors_entry() + trace__irq_vectors_exit() and use the
'vector' arg as I use the 'syscall id' one for syscalls.

Then the default for 'perf trace' will include irq_vectors in addition
to syscalls.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Luis ClÃudio GonÃalves <lclaudio@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-wer4cwbbqub3o7sa8h1j3uzb@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/builtin-trace.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 58bbe85..e71605c 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1528,7 +1528,8 @@ static int syscall__alloc_arg_fmts(struct syscall *sc, int nr_args)
 }
 
 static struct syscall_arg_fmt syscall_arg_fmts__by_name[] = {
-	{ .name = "msr", .scnprintf = SCA_X86_MSR, .strtoul = STUL_X86_MSR, }
+	{ .name = "msr",	.scnprintf = SCA_X86_MSR,	  .strtoul = STUL_X86_MSR,	   },
+	{ .name = "vector",	.scnprintf = SCA_X86_IRQ_VECTORS, .strtoul = STUL_X86_IRQ_VECTORS, },
 };
 
 static int syscall_arg_fmt__cmp(const void *name, const void *fmtp)